The disclosure of Japanese Patent Application No. 2001-085516 filed on Mar. 23, 2001, including the specification, drawings and abstract is incorporated herein by reference in its entirety.
1. Field of Invention
The invention relates to a vehicle performance evaluation test method and apparatus, and more particularly to a vehicle performance evaluation test method and apparatus for evaluating vehicle performance, using a pressing device that automatically applies pressure to a control member to be operated by a vehicle operator.
2. Description of Related Art
In order to conduct a test for evaluating braking performance such as a braking distance and deceleration of a vehicle, for example, a motor vehicle, a brake pedal needs to be depressed with a predetermined depressing force or the brake pedal needs to be depressed so as to achieve a predetermined deceleration while keeping the vehicle in a running state. It is, however, difficult for the vehicle operator to accurately operate the brake pedal as described above.
JP-A-11-132914 discloses a vehicle performance evaluation test apparatus that automatically operates the brake pedal for the vehicle operator. The test apparatus is fixedly set under a seat of the vehicle and is provided with a control rod which extends in a longitudinal direction of the vehicle and a driving mechanism which drives the control rod forward and backward in the longitudinal direction of the vehicle. The control rod serves to automatically operate the brake pedal with its tip such that the performance evaluation test is conducted with respect to the braking operation of the vehicle.
With the aforementioned test apparatus, the brake pedal can be automatically depressed, and therefore the vehicle operator is allowed to conduct the evaluation test for the braking operation of the vehicle without operating the brake pedal while driving the vehicle. Furthermore, since a main portion of the test apparatus is fixedly set under the seat, the possibility of interfering with the vehicle operator when he/she enters or exits the vehicle or to perform smooth driving is reduced.
In the aforementioned test apparatus, the driving mechanism is operated in accordance with a specific pattern, and accordingly, the brake pedal is depressed in accordance with a predetermined pattern. Depending on the type or state of the vehicle to be tested, the accuracy of the evaluation test may be deteriorated or the brake pedal cannot be depressed in a stable state.
It is one object of the invention to provide a performance evaluation test method for conducting the evaluation test with high accuracy irrespective of the type or state of the vehicle to be tested by depressing the control member in accordance with the actual state of the vehicle and by operating the control member in a stable state.
According to one aspect of the invention, a method of conducting a performance evaluation test for a vehicle is provided. The method is conducted by providing an actuator that applies a depressing force to a control member to be operated by a vehicle operator and a controller that controls the actuator by controlling the actuator to automatically apply the depressing force to the control member for conducting a performance evaluation test for the vehicle, and changing control of the actuator in accordance with an actual state of the vehicle. Another aspect of the invention relates to a performance evaluation test apparatus for a vehicle including an actuator that presses a control member to be operated by a vehicle operator, and a controller that controls the actuator so as to automatically press the control member for conducting a performance evaluation test for the vehicle. The controller changes control of the actuator in accordance with an actual state of the vehicle.
The control of the actuator may be varied in accordance with the actual state of the vehicle. Therefore the control member can be appropriately depressed by controlling the actuator in accordance with the actual state of the vehicle irrespective of the type of the vehicle to be tested. As a result, the evaluation test can be conducted with high accuracy irrespective of the change in the test conditions or state of the vehicle by operating the control member (e.g., a brake pedal) in a stable manner.
According to one aspect of the invention, the actual state of the vehicle is detected, and the actuator is controlled such that the vehicle is brought into a predetermined state in accordance with the detected actual state of the vehicle. The actual state of the vehicle is detected, based on which the actuator is controlled so as to bring the vehicle into a predetermined state. As the actuator can be surely and appropriately controlled in accordance with the actual state of the vehicle, the control member can be surely and appropriately depressed.
According to one aspect of the invention, the actual state of the vehicle is detected, and a parameter for the control of the actuator is changed in accordance with the detected actual state of the vehicle. The actual state of the vehicle is detected, based on which parameters for controlling the actuator are changed. Therefore the actuator can be surely and appropriately controlled in accordance with the actual state of the vehicle and the control member can be surely and appropriately depressed.
According to one aspect of the invention, the actual state of the vehicle represents a depressing force applied to the control member by the actuator. The actual state of the vehicle is represented by the depressing force applied to the control member by the actuator, and therefore the actuator is controlled in accordance with the depressing force to be applied to the control member. This makes it possible to control the depressing force applied to the control member to a desired depressing force accurately.
According to one aspect of the invention, the actual state of the vehicle represents a deceleration of the vehicle. The actual state of the vehicle is represented by deceleration of the vehicle, based on which the actuator is controlled. Hence the depressing force applied to the control member can be accurately controlled to achieve a desired deceleration of the vehicle.
According to one aspect of the invention, a running state of the vehicle is detected, and the depressing force applied to the control member is reduced by the actuator such that an evaluation test for the performance of the vehicle is stopped when it is determined that the running state of the vehicle is unstable. The running state of the vehicle is detected, and the depressing force applied to the control member is decreased to terminate the evaluation test when the running condition of the vehicle is unstable, and therefore the evaluation test can be surely prevented from being continued when the running condition of the vehicle is unstable.
According to one aspect of the invention, the control member takes form of a braking operation member, such as a pedal, for example. Since the control member takes form of the brake control member, it is possible to automatically conduct the evaluation test for braking operation of the vehicle by automatically depressing the brake control through the actuator.
Preferably, the actual state of the vehicle is varied based on which the control of the actuator changes in accordance with a type of the performance evaluation test conducted for the vehicle.
Preferably, the actual state of the vehicle represents a depressing force applied to the control member by the actuator when the performance evaluation test is conducted at a constant depressing force, and the actual state of the vehicle represents a deceleration of the vehicle when the performance evaluation test is conduced at a constant deceleration.
Preferably, a deviation between the predetermined state and the detected actual state of the vehicle is calculated, and the actuator is controlled so as to reduce the calculated deviation.
Preferably, the parameter for the control of the actuator represents a feedback control amount based on a deviation between the predetermined state and the detected actual state of the vehicle.
Preferably, the actuator is controlled by a feed-forward control amount obtained on the basis of the predetermined state of the vehicle, and then by the feed-forward control amount obtained on the basis of the predetermined state of the vehicle, and a feedback control amount on the basis of a deviation between the predetermined state and the detected actual state of the vehicle.
Preferably, the feedback control amount includes a proportional control amount and an integral control amount.
Preferably, the actuator is controlled by a feed-forward control amount obtained on the basis of the predetermined state of the vehicle, then by the feed-forward control amount and a proportional control amount of a feedback control obtained on the basis of a deviation between the predetermined state and the detected actual state of the vehicle, and subsequently by the feed-forward control amount obtained on the basis of the predetermined state of the vehicle, and the proportional control amount and an integral control amount of the feedback control obtained on the basis of the deviation between the predetermined state and the detected actual state of the vehicle.
Preferably, application of the depressing force to the control member is terminated upon stoppage of the vehicle.
Preferably, a yaw rate of the vehicle is detected, and it is determined whether a running state of the vehicle is unstable on the basis of the detected yaw rate of the vehicle.